Fractionator Fenske

On the gasoline fraction Fenske, Tongberg, and Quiggle (14, 58) Gooding, Adams, and Rail (23) Ward, Gooding, and Eccleston (59) Bell (4) and Cady, Marsch-ner, and Cropper (9). 

Neutralise the cold contents of the flask with 500-600 ml. of 40 per cent, aqueous sodium hydroxide solution, equip the flask for steam distillation and steam distil until about 1 litre of distillate is collected. The steam distillate separates into two layers. Add solid sodium hydroxide (< 100 g.) to complete the separation of the two layers as far as possible. Remove the upper (organic) layer and extract the aqueous layer with three 50 ml. portions of chloroform. Dry the combined organic layer and chloroform extracts with anhydrous potassium carbonate and distil the mixture through a short fractionating column (e.g., an 8 Dufton column) after a fore run of chloroform, followed by pyridine, collect the crude 4-ethylpyridine at 150-166° (49 g.). Redistil through a Fenske-... 

Refluxed with sodium wire, then fractionally distd twice through a Fenske (glass helices packing) column. 

Fractionators produce two results only (1) stream splitting, with so many pounds going out one end and all other feed pounds going out the other and (2) component segregation toward one or the other of the product streams, characterized by the Fenske ratio ... 

To the cooled mixture 6N hydrochloric acid is added drop wise with stirring, until no solid remains. The organic layer is separated, washed four times with 30-ml. portions of water (Note 6), dried over powdered calcium chloride (Note 7), and distilled through a 1 X 15 cm. column packed with Fenske helices (Note 8). The yield of benzene is 5.5-6.5 g. (70-83%), b.p. 80-82°, n20d 1.5007. The fraction boiling at 82-180° contains no unreacted chlorobenzene (Notes 9, 10, 11). 

Two hundred and sixty-seven grams (296 ml., 4.38 moles) of 28% aqueous ammonium hydroxide, 207.5 g. (209 ml., 1.57 moles) of paraldehyde, and 5.0 g. (0.065 mole) of ammonium acetate are heated to 230° with continuous agitation in a 2-1. steel reaction vessel (Note 1), and the temperature is maintained at 230° for 1 liour (Note 2). The autoclave is then allowed to cool, and the two layers of the reaction mixture are separated (Note 3). To (lie non-aqueous layer is added 60 ml. of chloroform, causing separation of water which is combined with the aqueous layer. I he aqueous layer is extracted with three 50-ml. portions of chloroform, and the extracts are combined with the main portion of the chloroform solution. After removal of the chloroform by distillation at atmosiiheric pressure, fractional distillation under reduced pressure through a 30-cm. Fenske-type column gives a fore-run of water, paraldehyde, and a-picoline, b.p. 40-60°/17... 

Pent-2-ene (mixed isomers) [109-68-2] M 70.1, b 36.4 , d 0.650, n 1.38003, n 1.3839. Refluxed with sodium wire, then fractionally distd twice through a Fenske column. 

Benzyl bromoacetate [5437-45-6] M 229.1, b 96-98°/0.1mm, 146°/12mm, 166-170°/22mm, 1.444, n2D5 1.5412. Dilute with Et20, wash with 10% aqueous NaHCO, H2O, dry (MgS04) and fractionate using a Fenske column. [JCS 1521 1956]. LACHRYMATORY... 

The contents of the flask are transferred to a 1.5-1. round-bottomed flask, 0.5-1 g. of copper carbonate is added, and the liquid is fractionally distilled in vacuo with the aid of a Fenske column (Fig. 1) (Notes 2 and 3). The following fractions are collected. 

The jmethod of O Connell is popular because of its simplicity and the fact that predicted values are conservative (low). It expresses the efficiency in terms of the product of viscosity and relative volatility, pa, for fractionators and the equivalent term HP In for absorbers and strippers. The data on which it is based are shown in Figure 13.43. For convenience of use with computer programs, for instance, for the Underwood-Fenske-Gilliland method which is all in terms in equations not graphs, the data have been replotted and fitted with equations by Ncgahban (University of Kansas, 1985). For fractionators,... 

Stereoelective Hydroformylation of 3-Methyl-1-pentene. The same apparatus and procedure as for styrene were used. 4.21 grams (0.05 moles) of 3-methyl-l-pentene were hydroformylated in 50 ml of dry, degassed mesitylene in the presence of 115 mg (0.125 mmole) of HRh(CO)-(P< >3)a and 249 mg (0.5 mmole) of ( — )-DIOP. After 70 hrs the conversion was 51.1%. The unreacted olefin and the aldehydes were separated with a 1-m rectification column filled with Fenske rings. The pure olefin (GLC) had [ ]d17 +1.25° (neat). The aldehydes could not be completely separated from the solvent through rectification. A fraction containing 58% of ( —) (R)-4-methylhexanal had < D25 —0.26°. 

In the years from 1940 through the 1960s, several notable shortcut fractionation methods were published. Of these, one method that included several of these earlier methods has stood out and is today more accepted. Fenske, Underwood, and Gilliland [9-12] are the core of this proposed method. Yet one more entry is added, the Hengstebeck [13] proposed method to apply multicomponent distillation. As these earlier methods pointed out only two component separations (called binary systems), the Hengstebeck added contribution is most important for multicomponent applications. 

For single separation duty, Diwekar et al. (1989) considered the multiperiod optimisation problem and for each individual mixture selected the column size (number of plates) and the optimal amounts of each fraction by maximising a profit function, with a predefined conventional reflux policy. For multicomponent mixtures, both single and multiple product options were considered. The authors used a simple model with the assumptions of equimolal overflow, constant relative volatility and negligible column holdup, then applied an extended shortcut method commonly used for continuous distillation and based on the assumption that the batch distillation column can be considered as a continuous column with changing feed (see Type II model in Chapter 4). In other words, the bottom product of one time step forms the feed of the next time step. The pseudo-continuous distillation model thus obtained was then solved using a modified Fenske-Underwood-Gilliland method (see Type II model in Chapter 4) with no plate-to-plate calculations. The... 

For the heavy and light hydrocrackates, the hydrocracker simulator includes a product fractionation subroutine which distributes components between adjacent fractionator cuts using a Fenske-type formulation. 

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